As illustrated in FIGS. 14(a) and 14(b), a known motor drive device (refer to PTL 1, for example) includes a first motor driving unit 110 that functions as a converter, and a second motor driving unit 120 that functions as an inverter. The first motor driving unit 110 and the second motor driving unit 120 are connected with each other through a pair of short bars 130.
With the motor drive device 100 described in PTL 1, the second motor driving unit 120 is replaced depending on a specification of a driving motor, and the like. At the time of replacement, the second motor driving unit 120 is moved toward a front side relative to the first motor driving unit 110, and another second motor driving unit 120 is inserted to the back side from the front side relative to the first motor driving unit 110.